depends your design. nowadays many windows all around balcony/rooms/kitchen, so even with grill doors on the front there are many other entries.

when you say grill do you mean extra steel door infront of the original door, or the one further out of your main door (if you like to leave shoes outside it maybe good idea), but the design is limited to condo management?.

for balcony, most condos uses big glass while they are locked it won't stop people. i have not seen people install grills behind their balcony access.

for rooms, some condos have big windows just to look good, you can put grills behind but that would really change the look. depends if there are any ledges for people to climb around.

for kitchen, same, depends whether there are ledges. but even without ledges they can just SWAT team rope down from above.

if small windows, easy to install grills, but nowadays all windows are big big pieces, how you install?

how do you do that? since usually highrise nowadays lots of glass panels.

if put grill, will change the looks.

or got simpler way to do?

you'd imagine the amount of noise would chaos a ruckus? but no, guess it was done daytime and folks though it was renovation works going on.

it's better to have the lock behind the grills, so it's harder to reach. for you, either way it's gonna be harder to reach from 1 side unless you don't padlock when you are inside.

nowadays many condo management insist on the grilles you showed, which is really not that strong it's actually designed in the 80's.

got any good samples on how to grill up balcony access, kitchen windows, bedroom windows those tall corner ones. like subtle way of doing it so it won't ruin the looks?

don't think people are so enthusiastic about sharing their security systems...

because i have yet seen people installing grills on their oversized windows.